This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A242602 #16 Jul 05 2018 20:30:48 %S A242602 0,0,0,1,1,1,-1,-1,-1,2,2,2,-2,-2,-2,3,3,3,-3,-3,-3,4,4,4,-4,-4,-4,5, %T A242602 5,5,-5,-5,-5,6,6,6,-6,-6,-6,7,7,7,-7,-7,-7,8,8,8,-8,-8,-8,9,9,9,-9, %U A242602 -9,-9,10,10,10,-10,-10,-10,11,11,11,-11,-11,-11,12,12,12,-12,-12,-12,13,13,13,-13,-13,-13,14,14,14,-14,-14,-14 %N A242602 Integers repeated thrice in a canonical order. %C A242602 See the comments under A242601 for the k-family of sequences s(k,n), k = 1, 2, ..., and n >= 0. The present sequence is s(3,k). See the Myerson-van der Poorten link, p. 4. %H A242602 G. Myerson and A. J. van der Poorten, <a href="https://www.jstor.org/stable/2974639">Some problems concerning recurrence sequences</a>, Amer. Math. Monthly 102 (1995), no. 8, 698-705. %H A242602 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,-2,2,0,-1,1) %F A242602 O.g.f.: x^3/((1 + x^3)^2*(1 - x)) = x^3/(1 - x + 2*x^3 - 2*x^4 + x^6 - x^7). %F A242602 a(n) = a(n-1) - 2*a(n-3) + 2*a(n-4) - a(n-6) + a(n-7), n >= 7, with a(0) = a(1) = a(2) = 0, a(3) = a(4) = a(5) = 1 and a(6) = -1. %F A242602 a(n) = floor((n+3)/6)*(-1)^floor((n+3)/3), n >= 0. %Y A242602 Cf. A242601, A152467 (unsigned version with three additional leading zeros). %K A242602 sign,easy %O A242602 0,10 %A A242602 _Wolfdieter Lang_, Jun 17 2014